The present disclosure relates generally to wireless communication between electronic devices and more particularly to providing a secure wireless link between two devices.
Wireless networks have become ubiquitous. The Institute of Electrical and Electronics Engineers (IEEE) has promulgated the 802.11 family of standards, also referred to as “WiFi,” for enabling electronic devices to communicate with each other. These standards (including 802.11a, 802.11b, 802.11g and 802.11n) define frequency, modulation, data rates, and message formats for communicating information between devices. In general, in an 802.11-compliant wireless network (also referred to as a “WiFi network”), there is a designated “access point,” often with a wired connection to the Internet, that manages the WiFi network. Among other operations, the access point can route messages between networked devices. The WiFi network has a name (generally configurable by a network administrator interacting with the access point), which the access point can periodically broadcast, and devices that know the name or discover the network name from the access point's broadcast can join the network by sending a “join” request to the access point. In general, an access point will route messages only between devices that have joined the network.
Of course, wireless signals are easily intercepted. Accordingly, the WiFi standards provide various security protocols such as Wired Equivalent Privacy (“WEP”), WiFi Protected Access (“WPA”), and IEEE 802.11i (also known as “WPA2”). These protocols provide that information sent on the network is encrypted and specify particular encryption techniques to be used. The WiFi network access point can be configured for a particular security protocol.
In general, a device joining a secure WiFi network is required to know a network-specific password or key that can be used to encrypt and decrypt messages. While this password or key is generally not communicated wirelessly between devices, the access point in a secure WiFi network can require any device attempting to join the network to prove that it knows the password or key, e.g., by correctly encrypting a random challenge. To connect a computer to a secure WiFi network, a user can obtain the password from the network administrator and enter it into the computer, e.g., in response to a prompt generated by a network configuration program executing on the computer.
Recently, however, the universe of WiFi-enabled devices has begun to expand beyond computers to include a range of peripheral devices. For example, wireless printers that use 802.11 standards for communication have been developed. Some peripheral devices have a limited user interface, making it difficult or impossible for a user to enter a password or key for a WiFi network into the device. Often, it is necessary to first connect the peripheral device to a computer via a wired interface (e.g., USB) in order to configure the WiFi interface, then switch the peripheral device to a wireless operating mode.